Elevator systems typically include a load weighing sub-system to provide information regarding a load applied to an elevator car. Conventional load weighing systems typically utilize load cells configured to directly detect a load applied to the elevator car. The load cells are disposed in a void between the elevator car and the hoistway frame. Recent elevator cars, however, have been designed as unibody cars which eliminate the void needed for disposing the load cells.
Alternatively, load cells can be coupled to the elevator car ropes to measure the rope tension. A change in the rope tension is then detected to determine when a load is applied to the elevator car. Friction realized by the elevator car ropes, however, can affect the measured tension and therefore vary the overall approximated detection and/or weight of the load.